The use of amorphous silicon in electrophotographic photoreceptors has been proposed in U.S. Pat. No. 4,265,991. In this approach, a silicon-based photoconductive layer is disposed on a support. Electrophotographic photoreceptors employing such a silicon-based photoconductive layer have distinct advantages in terms of mechanical strength, panchromaticity and sensitivity in the longer wavelength range as compared with conventional photoreceptors that employ inorganic photoconductive materials such as Se, tri-Se, ZnO and CdS, and organic photoconductive materials in photoconductive layers. However, these new photoreceptors have their own problems. Specifically, they produce a blurred image if they are left to stand in the atmosphere, especially in a hot and humid atmosphere. Moreover, when they are worn such as with the residual toner cleaning blade or paper stripping fingers in electrophotographic processes, their surface changes in such a way as to produce an image having "streak" defects. To eliminate these problems, a silicon-based light-sensitive layer provided with various surface layers having compositions such as Si/N, Si/O and Si/C that will not harm the hardness of the light-sensitive layer have been proposed in U.S. Pat. Nos, 4,394,426 and 4,394,425. These surface layers are effective in solving the aforementioned problems.
However, photoreceptors coated with such surface layers such as those with compositions of Si/N, Si/0, Si/C, etc., have a new problem in that upon repeated use in a hot and humid atmosphere for a prolonged period, they produced a blurred image and became no longer useful commercially.